Aircraft motor gearing



Sept. 29, 1942. F. GOSSLAU 2,297,214

' AIRCRAFT MOTOR GEARING Filed Oct. 12, 1938 4 Sheets-Sheet l /n venzorA Home y Sept, 29, 1942. F. GOSSLAU 2,297,214

' AIRCRAFT MOTOR \GEARING Filed Oct. 12, 1958 4 Sheets-Shet 2 In ven forI Gambia.

By I

' Attorney Sept. 29, 1942. F. GOSSLAU 2,297,214

AIRCRAFT MOTOR GEARING Filed 00. 12, 19 38 4 Sheets-Sheet s In ven {ofRitz Kayla.

Afforngy Y Sept. 29, 1942. F. GOSSLA U 2,297,214

AIRCRAFT MOTOR GEARING Filed Oct-12, 1938 4 Sheets-Sheet 4 In ven forPatented se ezo, 1942 Fritz Gosslau, Berlin c liarlottenburg, Germany,vestedin theAlienProperty Custodian.

1 Application October v12, 1938, Serial 234,730

In Germany 2 Claims.

The present invention relates to an aircraft motor and more particularlyrefers to an aircraft motor for high outputs. v v

The object of the present invention isv to pro-'- vide aircraft motorsof high outputs which are considerably greater than those obtainedhitherto with a motor unit. As the output of each cylinder may hardly beincreased above 100 horse'- power, the hitherto known highly developedconstructions of aircraft motors, i. e. the V-shaped series motor havingtwelve cylinders and the double star-connected motor having eighteencylin ders, cannot be used for obtaining outputs above 2000 horsepower.

To obtain such high outputs it-is possible to arrange a plurality ofstar-connected cylinders On the one hand due to the high weight of themain end of -theconnecting rod 'and on the other hand due to the slidingspeed owing to the large diameter of the crank pin, these stresses ofthe bearings are increased to an inadmissible degree. Moreover, thelarge massesof the driving unit on the long crankshafts render a furtherincrease of diameter of the shaft imperative for reasons'of the technicsof vibrations.

Consequently, it'has been supposed, that the construction of a motor, inparticular a motor for-high outputs in form of a star-connected seriesmotor is unsuitable and unusable. Therefore, in fact, up to now nosuitable star-connected 1 motor has been developed.

Now, it has been found, that in a surprisingly simple manner a largedriving unit for aircrafts having outputs of 2000 and more horsepowermay be provided.

According to the invention the addition of the outputs of the individualmotors and ,motor groups respectively from one end of the crankshaft tothe other are obviated. For this pur-- pose collecting shafts areprovided which have no cranks and which substantially are subjected totorsional stresses only. Simultaneously the crank.

drive or crank drives are so constructed, that always part of the outputonly is tr'ansmittedto the collecting shaft at the connecting point orconnecting points.- In connection with-certain modifications'of theinvention practically no torsional stresses result in the crank pins.

With. the use of the invention the drawback October 4, 193*:

(cue-ass) inherent to aircraft, having a plurality of motors,

due to the multiple resistance of the individual cars may be obviated bythe fact, that a plurality of motors' is combined to. a single drivingunit or group. In such a case a] plurality of motors either may drivethe same propeller or two pro- .pellers rotating in opposite directions.The advantage of an increased reliability of operation is thus obtainedwhich offer aircrafts having a plurality of motors. Moreover, thefurther advantage is obtained that by combining the motors theresistance of the drive unit is considerably reduced.

v These advantages may for instance be obtained in connection withstar-connected series motors in 'a very simple manner by the fact, thatthe output of the various crankshafts is transferred to the propeller bymeans of intermediate shafts which are provided with clutches allowingconnection or disconnection of individual star-connected cylindersduring operation.

' Hereby for instance the advantages are obtained, that very high driveoutputs may be combined in a few cars. Moreover, with reduced resistanceof the drive unit the possibility is given to provide more motors andthereby particularly reliable aircrafts.

Finally; the construction according to the in vention has the advantage,that owing to the remove] of a portion of the friction losses duringflight with the same reserve of fuel' greater ranges may be obtained.

ample.

" In these drawings:

four-row star-connectedmotor,

. Fig. 2shows another modification having two 40 collecting shafts,

Fig. 3 illustrates a further arrangement ac-.

cording to which the intermediate shafts are used for driving twopropellers in opposite directions, Fig. 4 represents a modification inwhich the crankshaft is subdivided,

Fig. 5 is a view similar to that of Fig. 4, but adapted for driving twopropellers,

Fig. 6 is a view of a modification corresponding I tothat shown in Fig.'7 havingtwo collecting on shafts and a subdivided crankshaft,

Fig.7 is a view similar to that of Fig. 6 showing a constructionadaptedfor driving two propellers rotating in opposite directions,

Fig; 8 represents a modification according to 66 which the outer end ofthe two parts of the Fig. 1 shows anarrangement of the driveof acrankshaft is provided with gear wheels and the reduction gear for thepropeller,

Fig. 9 represents a similar construction in which the driving end of theleft hand crankshaft carries a wheel having internal teeth for the driveof planet wheels of the propeller drive,

Fig. 10 shows a modification having a subdivided crankshaft, collectingshafts and clutches inserted in the latter,

' Fig. 11 illustrates a further modification having a subdividedcrankshaft, a collecting shaft and a clutch built in, and a propellergear,

- Fig. 12 finally represents a modification having a-subdividedcrankshaft, a collecting shaft and a clutch inserted in the latter,oneend of the one crankshaft carrying a wheel having internal teeth for thedrive of revolving wheels, and

Fig. 13 shows the arrangement of the cylinders of one of the engines.

In the arrangement of a driving unit of a fourrow star-connected motorshown in Fig. 1 the 'twotwo-throw crankshafts I are journalled inthemain bearings 2, 3 and 4 and have the crank pins 5, 6, 1 and 8. Thecrank pins 5, 6 and I, 8 are provided with common crank webs 9 and Irespectively. On the crank webs gear wheel rims I I, I2 are fixed whichcooperate with gear wheels |4, rigidly connected to the collecting shaftl3. Another gear wheel l6 fixed on the shaft 13 engages the gear wheel|1 fixed to the propeller shaft I8. In the present case, the propellershaft 18 extends coaxially to the crankshaft.

From the drawings the power transmission will at once be evident. Theoutputs of each individual star-connected cylinder directly act upon thecollecting shaft without the crank pins being subjected to torsionalstresses. Hereby it is possible to manufacture the crank pins and themain end of the connecting rod in the usual dimensions which, asexperience has shown, warrant an operation of the crankpin bearings freeof objection.

The arrangement'according to the invention, furthermore, allowsoperation of the propeller I8 with a smaller number of revolutions thanthe crankshaft as is often required.

Fig. 2 shows another embodiment of the construction according to theinvention. In this construction, the output is, by means of gear wheelsI4 and 5, transferred from the ear wheels H and I2 mounted on thecrankshafts upon intermediate shafts l9 and 20 and then by way of gearwheels 2|, 22 upon-the gear wheel I1 and the shaft It on the propeller.Due to the drive from both sides, the shaft I8 is relieved of radialstresses.

Fig. 3 shows an arrangement according to which the intermediate shaftsl9 and 20 are used in a simple manner for driving two propellers-23, 24in opposite directions. The gear wheel 22 mounted on the intermediateshaft 20 drives the gear wheel I1 fixed upon the shaft |8 of thepropeller 23. Rotatably mounted on the shaft 16 is a hollow shaft 25carrying the propeller 24.

The hollow shaft 25 is driven by a gear wheel 26 engaging the gear wheel2|. This arrangement has the advantage that the torsional moments andalso the so-called gyratory moments stresses also. But in all cases,parts of the total output only subject the individual pins to torsion.

Fig. 4 shows a further modification according to Fig. 1. The twointermediate shafts 21 and 30 are driven by the gear wheels 3| and 32which are connected to the inner ends of the subdivided crankshaft.

Fig. 5 shows a corresponding arrangement for the drive of two propellersrotating in opposite directions as has been described with reference toFig. 3.

Fig. 6 shows two three-throw crankshafts operatively connected'withintermediate shafts I9 and 20.

Fig. 7 shows the arrangement of two threethrow crankshafts in connectionwith the drive of two propellers rotating in opposite directions as hasbeen explained in connection with Fig. 3.

In this figure 58 and 59 designate the right hand crankshaft and theleft hand crankshaft respectively. The power transmitting gear wheelsconnected to the crankshafts are arranged on the left hand 'end of theshaft 58 and on the right hand end of the shaft 59. The two .ends arefacing each other and lie in the middle vided with internal teeth. Ifthe rim 39 rotates,

the gear wheels 40 roll on the gear wheel 4| rigidly connected to thecasing, whereby the support 42 and the shaft iii of the propeller aredriven with a corresponding reduction of gear.

Fig. 9 shows a similar construction according to which, however, on thedriving end of the'left hand crankshaft the wheel 43 having internalteeth only is provided for driving the planet wheel 40, the support 42and the shaft I8 of the propeller. The output of the rear crankshaft istransferred by means of the gear Wheels 34 and 31 to the intermediateshaft 36 and the gear wheels 38 and 43, the wheel 43 being rigidlyconnected to the'shaft I8. The reduction of gear .resulting from theplanet wheel drive is, for the drive by way of the gears 34, 31, 38, sodesigned that the wheel 43 mounted upon the shaft It has the same speedof rotation as the support 42.

In the construction shown in Fig. 10 the right hand crankshaft and theleft hand crankshaft are designated 66 and 'GI respectively. At the lefthand end of the right hand crankshaft 60 a ing the gear wheel whichengages another gear wheel 10 mounted upon the shaft 1| of a propeller12.

The gear wheel 10, moreover, engages another gear wheel 13 fixed upon ashaft 14 on which a clutch part 15 also is mounted. The other clutchpart 16 is arranged on a shaft 11 and may at will be connected anddisconnected to and from the latter by means of a coupling member 18.More over, a gear wheel I! is fixed to the shaft ll en-' gaging with agear wheel carried by'the right hand end of the crankshaft II.

According to the construction shown in Fig. 11 the right hand crankshaftand the left hand crankshaft are designated 00 and 0| respectively. Atthe outer end of the right hand crankshaft 00 a gear wheel 02 isprovided engaging with another gear wheel 03 mounted upon the collectingshaft 00. Moreover, a, clutch part 8 also is provided on the shaft 80which may be connected and disconnected at will to and from the shaft 04by means of a coupling member 86. The other clutch part 01 is mountedupon a shaft 00 carrying a gear wheel 09 which engages another gearwheel 90 in which is arranged a part SI of another clutch. The otherpart 02 of this clutch is arranged upon the left hand end of thecrankshaft II in such a manner, that it may be connected anddisconnected to and from this crankshaft by means of a coupling member93. Connected to the gear wheel 90 is a cylindrical proiection 9|provided with a toothed rim into which the planet wheels 05 and 96 mayengage which are rotatably mounted upon a support 01. The

latter is rigidly connected to the propeller 99 by means of the shaft90. The planet wheels 05 and 06 roll upon a rim I00 having internalteeth which may be rotated round the axis of -the shaft 00.

In the construction shown in Fig. 12 the right and left hand crankshaftsare designated with IOI and I02 respectively. At the outer end of theright hand crankshaft a gear wheel I0! is I provided engaging withanother gear wheel I04 rigidly mounted upon the shaft I05. Mounted onthis shaft also is the one part I06 of a clutch which may be connectedand disconnected to and from the'shaft I05 by means of the couplingmember I01. The other part I00 of this clutch is rigidly mounted upon ashaft I00 which carries another gear wheel I I0 engaging-with a gearwheel III.

At the left hand end of the crankshaft I02 a clutch part 2 is providedin such a manner, that it may be connected and disconnected to and fromthe crankshaft bymeans of the coupling member H3. The other part I ll oftheglast mentioned clutch is rigidly arranged upon a dish-- like supportIii rotating about the axis of the clutch parts H2, H4. The support II!is provided with a rim having internal teeth into which engage planetgear wheels IIO, II'I rotatably mounted upon a support III, and whichroll on another toothed rim II! which is rigidly mount ed at the oneside of a clutch part I20. The other clutch part I2] is mounted upon ashaft I22 and may be selectively connected and disconnected to and fromthe shaft I22 by means of a coupling member I23. Rigidly connected tothe haft I22 also is the gear wheel III described already above. On thisshaft I22 also the propeller I is provided.

.end of the shaft of the propeller.

The practical construction of the aircraft motor according tothe"present"inventionresults in substantial advantages. So for instance,the crank case may be subdivided. Hereby it is possible to useintermediatebearing walls of a single piece and rolling bearings.Moreover, means for driving auxiliary apparatus may also be provided atthe free ends of the crankshafts as well as the ends of the collectingor intermediate shafts.

If the motors are coupled with adjustable proprising in combination,coaxially disposed crankcrankshafts meshing with a small gear wheel onone of said collecting shafts, two driven shafts coaxially disposed withregard to said crankshaft, and a speed reducing gear mechanism fortransmitting the rotary motion from each of said collecting shafts toone of said driven shafts whereby said collecting shafts are driven at asubstantially higher speed than said crankshafts and said driven shafts.

2. A power transmitting unit for aircraft'com-' prising in combination,coaxially disposed crankshafts, a plurality of star-connected cylinderunits including pistons and piston rods cooperating with saidcrankshafts, said star-connected cylinder units being arranged coaxiallyin staggered relation, two collecting shafts disposed substantiallyparallel with said crankshafts for accumulation of the individualoutputs of said cylinder units, a large gear wheel on each of saidcrankshafts, said large gear wheels being arranged adiacent to eachother and meshing each with a small gear wheel on one of said collectingshafts, two driven shafts coaxially disposed with regard to saidcrankshafts, and a speed reducing gear mechanism for transmitting therotary motion from each of said collecting shafts to one of said drivenshafts whereby said collecting shafts are driven at a substantiallyhigher speed than said crankshafts and said driven shafts.

, FRITZ GOSSL'AU.

